package net.xdclass.online_xdclass.interceptor;


import com.fasterxml.jackson.databind.ObjectMapper;
import io.jsonwebtoken.Claims;
import net.xdclass.online_xdclass.utils.JWTUtils;
import net.xdclass.online_xdclass.utils.JsonData;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;

public class LoginInterceptor implements HandlerInterceptor {
    /**
     * 进入到controller之前的方法进行验证
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//       在getHeader中取token 不行就到getParameter没有就重新登陆
        try{
            String accesToken =request.getHeader("token");
            if (accesToken==null){
                accesToken=request.getParameter("token");
            }
            if(StringUtils.isNotBlank(accesToken)){
                Claims claims= JWTUtils.checkJWT(accesToken);
                if (claims==null){
                sendJsonMessage(response, JsonData.buildError("登陆过期,请重新登陆"));
                    return false;
                }
                Integer id=(Integer) claims.get("id");
                String name=(String) claims.get("name");
//                存储值可随时取
                request.setAttribute("user_id",id);
                request.setAttribute("name",name);
                return true;
            }
        }catch (Exception e){ }
       return false;
    }

    /**
     * 响应json数据给前端
     * @param response
     * @param obj
     */
    public static void sendJsonMessage(HttpServletResponse response,Object obj){
        try{
            ObjectMapper objectMapper=new ObjectMapper();
            response.setContentType("application/json; charset=utf-8");
            PrintWriter writer = response.getWriter();
            writer.print(objectMapper.writeValueAsString(obj));
            writer.close();
            response.flushBuffer();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}
